Postprandial effects of test meals including concentrated arabinoxylan and whole grain rye in subjects with the metabolic syndrome: a randomised study

BACKGROUND/OBJECTIVES: Prospective studies have shown an inverse relationship between whole grain consumption and the risk of type 2 diabetes, where short chain fatty acids (SCFA) may be involved. Our objective was to determine the effect of isolated arabinoxylan alone or in combination with whole grain rye kernels on postprandial glucose, insulin, free fatty acids (FFA), gut hormones, SCFA and appetite in subjects with the metabolic syndrome (MetS). SUBJECTS/METHODS: Fifteen subjects with MetS participated in this acute, randomised, cross-over study. The test meals each providing 50 g of digestible carbohydrate were as follows: semolina porridge added concentrated arabinoxylan (AX), rye kernels (RK) or concentrated arabinoxylan combined with rye kernels (AXRK) and semolina porridge as control (SE). A standard lunch was served 4 h after the test meals. Blood samples were drawn during a 6-h period, and appetite scores and breath hydrogen were assessed every 30 min. RESULTS: The AXRK meal reduced the acute glucose (P=0.005) and insulin responses (P <0.001) and the feeling of hunger (P=0.005; 0-360 min) compared with the control meal. The AX and AXRK meals increased butyrate and acetate concentrations after 6 h. No significant differences were found for the second meal responses of glucose, insulin, FFA, glucagon-like peptide-1 or ghrelin. CONCLUSIONS: Our results indicate a stimulatory effect of arabinoxylan on butyrate and acetate production, however, with no detectable effect on the second meal glucose response. It remains to be tested in a long-term study if a beneficial effect on the glucose response of the isolated arabinoxylan will be related to the SCFA production.